Circulation: Arrhythmia and Electrophysiology Topic Review (original) (raw)
Related papers
2011
The following articles are being highlighted as part of Circulation: Arrhythmia and Electrophysiology’s Topic Review series. This series will summarize the most important manuscripts, as selected by the editors, published in Circulation: Arrhythmia and Electrophysiology and the rest of the Circulation portfolio. The studies included in this article represent the most read manuscripts published on the topic of atrial fibrillation in 2009 and 2010. (Circ Arrhythm Electrophysiol. 2011;4:e76-e83.)
Circulation, 2013
This study reviews our experience in the surgical treatment of atrial fibrillation (AF) during the past 2 decades in 212 consecutive patients with lone AF. Freedom from AF in the original Cox-Maze III procedure was 93%. However, the procedure was difficult to perform and had a 10% rate of major complications. By using radiofrequency bipolar clamp technology to replace surgical incisions with transmural lesions, we modified the procedure (Cox-Maze IV), essentially maintaining the original pattern of lesions. Our results demonstrate that the procedure is much easier to perform, the time to perform the procedure is reduced, and the major complication rate declined to 1%. The present study shows that freedom from AF is still 90% and even off antiarrhythmics it is 83%. Thus, we were able to maintain the efficacy of the original procedure and make it more accessible to a wider cohort of patients. The Cox-Maze IV represents a therapeutic option for lone AF in patients who have had clinical symptoms despite medical treatment or in whom a catheter ablation has failed, patients who have had a stroke despite anticoagulation therapy, and patients who are not candidates for other therapies. The procedure can be performed with minimal risk. The results of this study also serve as a benchmark for the future development of procedures to treat lone AF. Conclusions: The Cox-Maze Procedure, although simplified and shortened by alternative energy sources, has excellent results, even with improved follow-up and stricter definition of failure. 1
Spatial Distribution and Frequency Dependence of Arrhythmogenic Vagal Effects in Canine Atria
Journal of Cardiovascular Electrophysiology, 2000
Methods and Results: VS (10 to 50 Hz, 1 msec, 15 V, 5-sec trains) induced single or multiple atrial premature depolarizations (APDs), and/or AF in 8 of 10 open cbest dogs. Occurrence of APDs and AF increased with increa.sing VS intensity. Epicardial mapping (254 unipolar electrodes) of botb atria sbowed tbat APDs as a rule emerged from ectopic sites, often from the right atrial appendage. Activation mapping of the first 10 cycles of AF showed that only a small number (<3 to 4) of unstable reentrant circuits were possible at the same moment. Moreover, most sustained VS-induced AFs were accounted for by a single leading stable reentrant circuit tbat activated the remainder of tbe atria.
Journal of Molecular and Cellular Cardiology, 2010
The electrical properties of the atria and ventricles differ in several aspects reflecting the distinct role of the atria in cardiac physiology. The study of atrial electrophysiology had greatly contributed to the understanding of the mechanisms of atrial fibrillation (AF). Only the atrial L-type calcium current is regulated by serotonine or, under basal condition, by phosphodiesterases. These distinct regulations can contribute to I Ca down-regulation observed during AF, which is an important determinant of action potential refractory period shortening. The voltage-gated potassium current, I Kur , has a prominent role in the repolarization of the atrial but not ventricular AP. In many species, this current is based on the functional expression of K V 1.5 channels, which might represent a specific therapeutic target for AF. Mechanisms regulating the trafficking of K V 1.5 channels to the plasma membrane are being actively investigated. The resting potential of atrial myocytes is maintained by various inward rectifier currents which differ with ventricle currents by a reduced density of I K1 , the presence of a constitutively active I KACh and distinct regulation of I KATP . Stretch-sensitive or mechanosensitive ion channels are particularly active in atrial myocytes and are involved in the secretion of the natriuretic peptide. Integration of knowledge on electrical properties of atrial myocytes in comprehensive schemas is now necessary for a better understanding of the physiology of atria and the mechanisms of AF.
IEEE engineering in medicine and biology magazine : the quarterly magazine of the Engineering in Medicine & Biology Society, 2006
Since November 2000, he is the chair of the department. His research interests are mainly in the following topics: biomedical signal processing (ECG, blood pressure signal and respiration, cardiovascular variability signals, EEG, and evoked potentials), cardiovascular modeling, neurosciences, medical informatics, and regulation and standards in medical equipment and devices. Since March 1983, he has also taught a course at a graduate level on biomedical signal processing at Engineering Faculties (Milan and Roma) and at Specialization Schools of Medical Faculties (Milan and Roma). He was an elected member of the IEEE-Engineering in Medicine and Biology Society
Electrophysiologic studies in atrial fibrillation
The American Journal of Cardiology, 1983
ExtrasUmulus-induced intraatrial conduction delays were measured in 12 patients with documented episodes of atrial fibrillation (AF) by recording atrial electrograms at the high right atrium, His bundle region, and coronary sinus, Seventeen patients with and without heart disease, but without atrial arrhythmias served as the control group. During baseline-paced atrial rhythms, a conduction delay zone could be delineated, near the atrial effective refractory period, during which all extrastimuli produced conduction delays. When compared at the same paced cycle lengths (500 to 650 ms), the patients with AF had shorter atrial effective refractory periods mean -4-standard deviation 206 4-24.1 versus 233 4-28.2 in control patients, p <0.02), wider conduction delay zones (79 4-21.7 ms versus 52 -t-21 in control patients, p <0.01), and longer conduction delays both to the His bundle region (64 -I-18.3 ms versus 35 -I-21.7 in control patients, p <0.005) and the coronary sinus (76 -I-18.9 ms versus 35 -t-16.1 in control patients, p <0.001).